Canal lock



Dec. 28, 1937. ROTHMUND 2,103,871

CANAL LOCK Filed April 23. 1935 450/ 010 firml v0 ATTORNEY Patented Dec. 28, 1937 UNITED- STATE CANAL LOCK Leopold Rothmund, Stuttgart, Germany Application April 23, 1935, Serial. No. 17,760

In Germany May 12, 1934 3 Claims.

, My invention relates to. locks for ships to raise. and lower them from a lower water level to a higher water level and vice versa: respectively. More particularly, my invention relates to locks 5 of the type wherein twofloating or diving troughs are: provided in the lock" basin or lock chamber. While one of these troughs is in its highest position, in which its inner space can be brought into communication with the upper water level, the other trough occupies its lowest position, in which its inner space can be brought into communication with the lower water level. For the purpose of raising or lowering a ship, one of the two troughs is: lifted by a; lifting gear, while simultaneously therewith the other trough is-l'owered'. To enable these operations-to be performed with a comparatively small consumption of power, the troughs are provided underneath their closed bottoms with 'an open bottomed air-chamber, o which chambers contain air under pressure, the air:- chamber: of one trough. being in communication with that of theiother trough by an air-conduit. In this mannenstheiweightsof the troughs resting on: an. airi-c'ushionare balanced relative o to each otherpand "as the. compressed air from theuair-chamber of the-descending trough is allowed to passzthrough" said conduit to the airchamber of the rising trough, it is'evidentthat only a' comparatively :small consumption of power is required for the lifting and the lowering of the'two troughs. I r

Now, if the troughs are disposed, as has been done heretofore, in a lock basin connected with the lower water level, there result certain disadvantages. For instance, the troughs will have a secure'floating position. only when intheir lowest position."

Moreover, as is natural, the air pressure in such lower-level troughs is small, since the pressure ty degree lower than the ceiling of the air-chain her in the lower-level position of the J trough.

Furthermore, whenlsu'ch a lower-level trough I level in'the air-chamber is only by a slight sa;te'

of the troughs. The air-cushion in the airchamber of the trough'must always be equal to theheight of the stage of the lock, and every variation in temperature must, therefore, be taken care of in that in case of a temperature increase .air must be permitted to escape, whereas in case of a decrease in temperature additional:

compressed air must be supplied. Eventually, an auxiliary float must be provided to avoid the dis:-

advantages due to temperature .changesof the,

compressed air in theair-chamber, 7 To further insure in lower-level troughs a. uniform buoyancy, their walls must be given a certain inclination, which will be the more pronounced, the more the walls, for reasons of safety, have been artificially reinforced; The'disadvantage resulting therefrom is that, except in the' intermediate. position of two cooperating troughsthe border faces between air-cushion and pressure level in the air-chambers, which control the amount of the buoyancy, no longer correspond so that with equal speed of the two troughs, asis'a requisite in theinterest of the simplicity and security of the operation, the, liftlng gear must do considerable additional work.

These disadvantages areavoided by the present invention, according to which the floating troughs are disposed in a lock basin which is in communication with the upper water level, and according to which, moreover, the troughs and their air chambers areso designed, that also in the upper level position of a trough its air chamber remainsimmersed in the water, stationary air conduits being provided for conducting air under pressure from the air chamber of one trough to the air chamber of the other trough, the arrangement being such that the troughs can so far descend that their water level will be adjusted to the lower water level. The troughs, therefore, are upper water level troughs whereby, as compared with lower water level troughs, the following advantages are secured. The airchamber of an upper-level trough is always below water, and the trough has in the upper level position a uniformly secure floating position. Moreover, in the upper-level trough the pressure level, that is to say, the border-layer between the air-cushion and the water-level, must be disposed below the ceiling of the air-chamber about the amount of the depth of the immersion so that the air-pressure is correspondingly higher necessitating greater strength of thewalls of the air-chamber. An artificial reinforcement of the walls of the'trough, therefore, can be dispensed with. Because of its strong walls and the fact that the air-cushion commences about 3-4 meters below the level of the basin, an upper-level trough is superior to a lower-level trough. Moreover, the air-cushion in the air-chamber of an upperlevel trough is only slightly affected by variations in temperature, so that these variations can be readily compensated for with a small compressor. Because the air-chamber of an upper-level trough is below water and always remains below water, involves the further advantage that having perpendicular walls, the trough has .a uniform buoyancy in every position.

The air-chambers of two cooperating troughs may be in communication with each other by a stationary air-conduit located below the water level in the trough-basin, or they may also be con nected with each other by an air-conduit suspended above said water-level.

In the latter case, the arrangement is such that the air-chambers are automatically engaged with the air conduit when rising and are automatically disengaged from the air-conduit when descending. In order to enable such an automatic engagement and disengagement, there are provided at the lower ends of the air-conduit as well as at the places in the air-chambers of the floating .troughs to be connected with the air-conduit specially constructed parts which are concentrically arranged relative to each other so that the parts provided on the air-chambers of the troughs surround the corresponding parts provided at the lower ends of the air conduit, through which the compressed air pendulates between the air-chambers of two cooperating troughs.

My invention will now be further described with reference to the appended drawing, in which, by way of illustration, I have shown diagrammatically an embodiment of my invention and in which Fig. 1 is a section through a lock-basin and two cooperating floating troughs therein provided with open-bottomed air-chambers and a stationary airconduit below the level of the water; Fig. 2 is a sectional view showing two cooperating floating troughsand an air-conduit suspended above the water-level and arranged for automatic engagement with and disengagement from the air-chambers of the two troughs. I

In Fig. 1, a denotes the lock basin. b and b denote the two cooperating floating troughs. As shown, each trough is provided with an open-bottomed air-chamber c and respectively. At d is shown a stationary air-conduit, whereby the two air-chambers c and c communicate with each other.

As shown in Fig. 1, the trough b is in its highest position, while the trough h is in its lowest position. When the compressed air in the air-chamber c is conducted through conduit d to the airchamber 0, the position of the two troughs will be reversed, that is to say, the trough b will descend to its lowest position, while the trough b will ascend to its highest position. When the troughs occupy the highest position, the water level therein will be at the same height as the water level in the lock-basin. 9 denotes the height of the waterlevel in the trough b when the latter occupies its lowest position.

, As will, therefore, appear from Fig. 1, the proportion between the amount of the pressure in the air chambers and the weight of the troughs is so selected, that is to say, the'height of the air chambers is so suited to that proportion, that in the elevated position of the troughs, as represented in Fig. 1 by the trough b, the pressure level lies below the ceiling of the air chamber the same amount as the pressure level remains in the lowest position of the trough below the ceiling of the air chamber, which amount is made up of the floating height H and the safety margin H.

According to Fig. 2, communication between the airchambers of the two floating troughs is established by an air conduit suspended above the upper water level in the lock-basin. The two troughs and their corresponding air-chambers are designated by the same reference characters as in Fig. 1, that is to say, b denotes the trough occupying the upper level position and 1) denotes the other trough shown in the position just prior to its descent, while 0 and 0' respectively denote the corresponding open-bottomed air-chambers. Communication between the two air-chambers is established by'the following means.

At 71, is indicated a supporting structure for an inverted U-shaped pipe i. The downwardly directed perpendicularly disposed portions 2'' and i of tube 1' aremade to a certain height with double walls forming an annular container closed at the bottom and open at the top. Over the perpendicular portions of pipe i is placed a movable pipe open at the top and bottom and having its lower portion also made of double walls so that an annular container is formed closed at the top and open at the bottom. The inner wall of this annular container is made to engage at the top the annular container formed by 2" and i Thethird element of the suspended air-conduit is a pipe 7c securely mounted on the top of air-chamber (c, c). This pipe 7c is also made with, double walls as shown, forming an annular container which is closed at the bottom and open at the top. The inner width of I is such that k and y can be readily telescoped relative to each other so as to form a closed conduit.

As will be evident from the drawing, a communication between the two air-chambers c and c existsonly during the descent and the ascent respectively of the two troughs. Shortly after the descending trough has commenced its immersing movement, the communication between the two air-chambers becomes automatically disconnected to be automatically re-established only when the immersed trough as it ascends reaches a position close to the upper water level. While the immersing trough descends, the other trough is at rest.

The air-tight seals between the three pipes or elements are effected by the above said annular or cylindrical containers being filled with water so that the compressed air is always shut off by a water column a to which corresponds the pressure of the compressed air in the air-chambers c and c. There is always a water-seal between i and 7', whereas the water-seal between a and 7c is automatically effected.

As compressed air is passed from the air-chamber 0 through the pipe i to the air-chamber c, the position of the two troughs b and b is reversed, that is to say, the trough b descends, while the trough b ascends.

My invention is, of course, not limited to the disclosure as herein presented, sincemy invention is capable of various embodiments.

I claim:

1. In combination with a waterway having an upper water level portion including a lock basin having the same water level as said upper water level portion, a lower water level portion, and gates between said lock basin and said lower Water level portion; a pair of floating troughs in said lock basin one to be elevated while the other is lowered and vice-versa, said troughs having end gates, each trough also having as a fixed part thereof an open-bottom air chamber closed at its top and sides, and an air conduit connecting said air chambers, said air chambers being disposed relative to said. troughs so as to be at all times completely submerged in the water of the lock basin. 7

2. The combination as set forth in claim 1 in whichairunder a predetermined pressure is present in the air conduit and in the air chambers, in which said air conduit is of U-shape and has a fixed position at all times completely below the level of the water in the lock basin and includes a pair of legs disposed, respectively, in

and in which an air seal is provided between each leg and the air chamber of the related trough, each air seal comprising an open-top closed-bottom water chamber surrounding the lower portion of the conduit leg, an open-top closed-bottom water chamber carried by the trough in surrounding relationship to said first mentioned air chamber, a tube open at its ends and slidably mounted on the conduit leg in surrounding rela tionship thereto and having its lower end portion disposed in said first mentioned water chamber, a second tube carried by said first mentioned tube in surrounding relationship thereto and cooperating therewith to provide a third water chamber closed at its top and open at its bottom, the lower end portion of said second tube being disposed in said second mentioned water chamber, and water in said water chambers, the top edge of the inner wall of said second mentioned water chamber serving by abutment with the top wall of said third water chamber to effect lifting of said tubes when the trough is elevated.

LEOPOLD ROTHMUND. 

